The water supply has been cut off temporarily because the workers one of the main pipes. (2013·天津，13)
A. had repaired
B. have repaired
C. repaired
D. are repairing
网友回答
A. had repaired
B. have repaired
C. repaired
(答案→)D. are repairing
解析：
考查动词时态。句意为：水供应已暂时被切断，因为工人们正在维修其中一个主管道。根据has been cut off判断应该是现在的某种时态。再根据时间状语temporarily可以判断出repair是现在正在发生的动作，故用现在进行时。